Natural Agents for Weed Control

Overview

There's no getting around weeds in the yard and garden. Chemical herbicides pollute groundwater and aren't always effective. Natural solutions, such as mulching, organic herbicides and no-till methods, may require more work at first, but produce better long-term solutions. No method is perfect, though, and most yards have a few weeds with even the most vigilant care.

Culture

Good cultural practices keep plants healthy. Healthy plants crowd out weeds and are less vulnerable to weed damage. Lawns are healthiest when kept at a height of 3 inches (for most varieties) according to Cornell University Garden Resources. Additionally, Cornell recommends fertilizing in the fall instead of the spring and watering lawns deeply, but infrequently. Choosing disease-resistant plants for vegetable and flower gardens minimizes the chance of disease affecting plants.

Organic Herbicides

Corn gluten is a non-toxic pre-emergent herbicide that contains the same ingredients as cat food. It works by forming a thin, protective layer over the soil that prevents weeds from germinating. Corn gluten costs more than synthetic pre-emergents and tends to work best when applied for two or three years. It doesn't affect weeds that have already sprouted and it prevents all plants, including grasses and flowers, from germinating, so it's best used on established lawns and beds.

Planting Practices

Vegetables grown more closely together in blocks instead of rows minimize weed growth. As the plants grow, they crowd out and shade most weeds. Additionally, plants produce more vegetables in a smaller garden space.

Mulches

Mulches, such as wood chips, bark, pine needles, shredded leaves and gravel, are effective at preventing most weed growth. Mulches also conserve moisture and act as insulation, regulating soil temperature and preventing heaving in the winter. Wood mulches slow soil warming in the summer, so rake them away from plants in early spring. Gravel mulches can retain too much heat in the summer and are best avoided around tender perennials.

Hand-Weeding

Pulling weeds by hand or cultivating them with a hoe is a necessary, if tiresome, part of maintaining a garden. The best strategy is to spend one or two hours weekly removing weeds from flower and vegetable gardens. Pulling weeds when the soil is moist and while weeds are still small simplifies the task. Weeds grow either by underground runners or by producing seeds. If weeds are consistently pulled before they're allowed to go to seed or grow rampantly, fewer will return the following season.

No-Till Methods

Tilling vegetable gardens brings weed seeds to the surface, introducing them into the garden. Raised beds require less tilling because they don't become compacted. Gardeners simply plant seeds directly in the soil each spring, reducing the number of weed seeds.

Keywords: organic weed control, natural weed control, weeds in garden

About this Author

Julie Christensen has been writing for five years. Her work has appeared in "The Friend" and "Western New York Parent" magazines. Her guide for teachers, "Helping Young Children Cope with Grief" will be published this spring. Christensen studied early childhood education at Ricks College and recently returned to school to complete a degree in communications/English.